It is state of the art, that a carbon particulate filter stores carbon particulate in the so-called adsorption operation. Carbon particulate filters can be used in Diesel engines or in an Otto engine. When using in a Diesel engine, they are also called Diesel particle filters. When the carbon particulate filter is at least nearly completely saturated and no further carbon particulate can be accommodated, it has to be burned off by means of a regeneration. As an input parameter for a control strategy for starting a regeneration, generally a carbon particulate saturation of 80% to 90% of a complete saturation is used. For starting a regeneration, different measures exist, of which one for example is to heat the exhaust-gas additionally by means of corresponding measures, for example by means of a heating operation of the combustion engine arrangement, so that the carbon particulate is heated up to the carbon particulate ignition temperature and is burnt in the filter with the oxygen contained in the exhaust-gas. These control strategies known from the State of the Art have the consequence, that a regeneration has to be started inevitably at the determined saturation limit of 80% to 90% and even then, when the combustion engine is not in a load condition suitable for the regeneration. If the regeneration would not be started, the carbon particulate saturation would further increase and the exhaust-gas back pressure would increase critically. In a forced regeneration, the exhaust-gas can be relatively cool because of an existing partial load operation, so that this has to be heated by means of injection of additional fuel during the heating operation to the necessary temperature. The energy input for heating the carbon particulate filter is thus relatively high. Furthermore, these control strategies regularly lead to the fact, that the regeneration is carried out to the complete carbon particulate burning-off. This can lead to an increased fuel consumption as well as, depending on the method for increasing the temperature, to a dilution of the lubricant oil with fuel.
DE 10 2007 027 182 A1 shows a method for the regeneration of a carbon particulate filter, which foresightfully includes traffic influences into the regeneration strategy. In this case, an input parameter into the method is the average speed of the vehicle. It shall be achieved, that only then a regeneration is started, when this will not have to be stopped prematurely.
EP 2 065 582 B1 shows a method for the regeneration of a carbon particulate filter, which for determining the saturation condition considers the influence of different operating conditions of the vehicle on the filter saturation. In this case values characterising the statistical driving conditions are included in the determination of the saturation condition. Different driving conditions can be idling operation, driving in the countryside or driving on the motorway.
Starting therefrom, it is an object of the present invention to reduce the energy input for the regeneration of a carbon particulate filter.